Extraction of alkyl lead compounds from organometallic complexes

ABSTRACT

Alkyl cyanide compounds are disclosed as addition agents for improving the liquid-liquid extraction of alkyl lead compounds from mixtures thereof with organometallic complexes with an extraction medium comprising iso-octane.

United States Patent William H. Harwood;

Kang Yang, both of Ponca City, Okla. 783,395

Dec. 12, 1968 Sept. 21,1971

Continental Oil Company Ponca City, Okla.

lnventors Appl. No. Filed Patented Assignee EXTRACTION OF ALKYL LEADCOMPOUNDS FROM ORGANOMETALLIC COMPLEXES 5 Claims, No Drawings ReferencesCited UNITED STATES PATENTS Shapiro et al McKay Ziegler et al.. Acciarriet a1.

Smeltz Primary Examiner-Tobias E. Levow Assistant ExaminerH. M. S. SneedAttorneys-Joseph C. Kotarski, Henry H. Huth, Jerry B.

Peterson, Jack N. Shears and Carroll Palmer 260/437 260/437 260/437260/448 A 260/437 X 260/437 260/437 X ABSTRACT: Alkyl cyanide compoundsare disclosed as addition agents for improving the liquid-liquidextraction of alkyl lead compounds from mixtures thereof withorganometallic complexes with an extraction medium comprisingiso-octane.

EXTRACTION OF ALKYL LEAD COMPOUNDS FROM ORGANOMETALLIC COMPLEXESBACKGROUND OF THE INVENTION Chem. 141, 161 (1924) who obtainedtetraethyl lead by electrolyzing sodium zinc triethyl at a lead anode,and by Ziegler in British Pat. No. 814,609 (1959) who disclosessynthesis of Group II-V metal alkyls by electrolyzing a complex aluminumalkyl at an anode composed of the Group II-V metal. Numerous otherreferences disclose similar processes.

Iso-octane has been disclosed as an extraction medium for theliquid-liquid extraction of alkyl lead compounds from mixtures thereofwith organometallic complexes. Though extraction occurs, there areproblems which are vexing. One of the worst is the emulsification of theiso-octane, so that good recovery is difficult.

SUMMARY OF INVENTION According to this invention an alkyl cyanide isutilized to improve the liquid-liquid extraction separation of alkyllead compounds from mixtures thereof with organometallic complexes withan extraction medium comprising iso-octane.

DETAILED DESCRIPTION ln carrying out the process of the invention, thealkyl cyanide can be added to the organometallic complex and alkyl leadmixture and the liquid-liquid extraction then accomplished by addingiso-octane to said mixture. When this method is followed there is noemulsification of the iso-octane and the separation is markedlyimproved. When the same method is followed but no alkyl cyanide isadded, emulsification of the iso-octane occurs and the recovery of thealkyl lead compound is more difficult. The following example illustratesthe process of this invention.

EXAMPLE To determine the extraction process, 80 cc. of KAlEt Cl and 80cc. of acetonitrile were mixed and tetraethyl lead was then added to themixture. Various concentrations of tetraethyl lead were used. Thesesamples were then each extracted with 40 cc. of iso-octane, and thenanalyzed chromato- Average =91 .48

Thrown out in averaging.

Extraction: cc KAIEQCI 80 cc CH CN extracted with 40 cc lso-octane +TELThe alkyl cyanides suitable for this process include those which havealkyl groups ranging from about one to about three carbon atoms.Examples of such compounds are acetonitrile, propionitrile andn-butyronitrile.

The concentration of alkyl nitrile in said system for best resultsshould range from about 20 to about 80 volume percent and preferablybetween about 40 and about 50 volume percent.

Having thus described the invention by providing specific examplesthereof, it is to be understood that no undue limitations orrestrictions are to be drawn by reason thereof, and that many variationsand modifications are within the scope of the invention.

What is claimed is:

1. In the liquid-liquid extraction of alkyl lead compounds from mixturesthereof with an organometallic complex KAlEtgCIg with an extractionmedium comprising iso-octane, the method of reducing the emulsificationof said mixture which comprises adding thereto an effective amount of analkyl cyanide.

2. The method of claim 1 wherein said alkyl lead compound is tetraethyllead.

3. The method of claim 1 wherein the alkyl group of said alkyl cyanidecontains from about one to about three carbon atoms.

4. The method of claim 3 wherein said alkyl cyanide is acetonitrile.

5. The method of claim 1 wherein said alkyl cyanide is present inconcentrations of from about 20 to about 80 volume percent.

2. The method of claim 1 wherein said alkyl lead compound is tetraethyllead.
 3. The method of claim 1 wherein the alkyl group of said alkylcyanide contains from about one to about three carbon atoms.
 4. Themethod of claim 3 wherein said alkyl cyanide is acetonitrile.
 5. Themethod of claim 1 wherein said alkyl cyanide is present inconcentrations of from about 20 to about 80 volume percent.